JIT: Assertion failed 'HBtab->ebdTryBeg->HasFlag(BBF_DONT_REMOVE)' in during 'Remove empty try/catch/fault'

[amanasifkhalid]

Failing in R2R legs of runtime-coreclr outerloop (example run). Antigen is also catching this (example run); here's a reduced repro on win-x64:

// Found by Antigen
// Reduced from 26.41 KB to 2.24 KB.


using System;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
using System.Runtime.Intrinsics;
using System.Runtime.Intrinsics.Arm;
using System.Runtime.Intrinsics.X86;
using System.Numerics;
public class TestClass
{
    static Vector<ulong> s_v_ulong_57 = Vector.Create((ulong)54);
    bool bool_66 = true;
    Vector<ulong> v_ulong_118 = Vector.Create((ulong)54);
    private static List<string> toPrint = new List<string>();
    public void Method0()
    {
        unchecked
        {
            try
            {
            }
            catch (System.ObjectDisposedException)
            {
            }
            finally
            {
                try
                {
                    Vector256.AsUInt64(Vector256<long>.Zero);
                }
                catch (System.MethodAccessException)
                {
                }
                catch (System.OutOfMemoryException)
                {
                    try
                    {
                    }
                    catch (System.TimeoutException)
                    {
                    }
                    catch (System.OverflowException)
                    {
                    }
                    finally
                    {
                        try
                        {
                            bool_66 = Vector.GreaterThanOrEqualAll(v_ulong_118 += s_v_ulong_57 - v_ulong_118+ v_ulong_118 ^ v_ulong_118^ v_ulong_118 + v_ulong_118, v_ulong_118 += s_v_ulong_57 - v_ulong_118+ v_ulong_118 ^ v_ulong_118^ v_ulong_118 + v_ulong_118);
                        }
                        catch (System.NullReferenceException)
                        {
                        }
                        catch (System.EntryPointNotFoundException)
                        {
                        }
                        finally
                        {
                        }
                    }
                }
                catch (System.RankException)
                {
                }
            }
            return;
        }
    }
    public static void Main(string[] args)
    {
    }
    public static int Antigen()
    {
        new TestClass().Method0();
        return string.Join(Environment.NewLine, toPrint).GetHashCode();
    }
}
/*
Environment:

set DOTNET_JitStressEvexEncoding=1
set DOTNET_JitClassProfiling=0
set DOTNET_TieredCompilation=0
set DOTNET_PreferredVectorBitWidth=512
set DOTNET_JitStressRegs=0
set DOTNET_JitThrowOnAssertionFailure=1
set DOTNET_LegacyExceptionHandling=1

Debug: 1538163399

Release: 0
JIT assert failed:
Assertion failed 'HBtab->ebdTryBeg->HasFlag(BBF_DONT_REMOVE)' in 'TestClass:Method0():this' during 'Remove empty try/catch/fault' (IL size 222; hash 0x46e9aa75; FullOpts)

    File: D:\a\_work\1\s\src\coreclr\jit\jiteh.cpp Line: 3236


*/

cc @dotnet/jit-contrib @AndyAyersMS

[dotnet-policy-service]

Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch
See info in area-owners.md if you want to be subscribed.